FINAL DRAFT

CRITERIA FOR THE USE OF SURROGATE DATA

Prepared by the ABRWH Work Group on Use of Surrogate Data

May 14, 2010

For the purposes of this report, the term “surrogate data” will refer to the use of exposure data from

one site for individual dose reconstruction for workers at another site.  In reviewing this topic for the

Work Group SC&A distinguished between “Type I” surrogate data use (as described above) and “Type II”

surrogate data where these data are used as part of a scientific effort to develop parameters for use in

dose reconstruction activity calculations rather than as a substitute for the lack of adequate data

needed for dose reconstruction.   

“Surrogate data” are used in the NIOSH dose reconstruction program because of the lack of complete

and comprehensive exposure monitoring records for many of the workers at the sites covered by the

program (SC&A September 2007).  It is more often considered  for dose reconstruction during the early

years of some DOE and AWE facilities because of the lack of reliable monitoring methods, the urgency of

developing production capabilities, and other reasons.   

This report will review a number of criteria that need to be considered in determining whether the

specific use of surrogate data for individual dose reconstruction is scientifically sound and appropriate

for that particular application.  

1. Hierarchy of Data – It should be assumed that the usual hierarchy of data would apply to dose

reconstructions for that site ( Individual worker monitoring data followed by co‐worker data

followed by workplace monitoring data such as area sampling followed by process and source

term data.)  This hierarchy should be considered when evaluating the potential use of surrogate

data.  Surrogate data should only be used to replace data if the surrogate data have some

distinct advantages over the available data and then only after the appropriate adjustments

have been made to reflect the uncertainty inherent in this substitution.

2. Exclusivity Constraints – In many cases, surrogate data are used to supplement the available

monitoring data from a site.  In those cases, the surrogate data is usually used to justify certain

assumptions about the distribution or range of possible exposures or assumptions about the

source terms.  In those cases, no special justification is necessary beyond the usual scientific

evaluation. This is akin to the Type II use decribed above.  However, in other situations, there

are no or very little monitoring data available.  In those cases, the use of the surrogate data as

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the basis for individual dose reconstruction would need to be stringently justified.   This

judgment needs to take into account not only the amount of surrogate data being relied on

relative to data from the site but also the quality and completeness of that surrogate data.   

3. Site or Process Similarities – One of the key criteria for judging the appropriateness of the use of

surrogate data would be the similarities between the site (or sites) where the data were

generated and the site where the surrogate data are being utilized.  The application of any

surrogate data to an individual dose reconstruction at a site should include a careful review of

the rationale for utilizing that source of data. Factors that could be considered include, but are

not limited to, similarity of the production processes, presence or absence of conditions that

might affect exposure, and monitoring methods employed at the site(s).   The potential

availability of other sources of surrogate data needs to be considered  and the selection of the

surrogate data used for dose reconstruction justified. Some of the questions to be considered

where appropriate are:  

• Are there other sources of surrogate data that were not used ?  

• Do these other potential sources contradict or undermine the application of the

data from the selected site?   

• Are there adequate data characterizing the site being used that would help

support its application to other sites?   

• Do the surrogate data reflect the type of operations and work practices in use at

the facilities in question?    

Surrogate data should not be used if the equivalence of working conditions, source

terms, and processes of the surrogate facility to the one for which dose reconstructions are

being done cannot be established with reasonable scientific or technical certainty as outlined

here.

4. Temporal Considerations: Consideration also needs to be given to the period in question, since

working conditions and processes varied in different periods.  Surrogate data should belong in

the same general period as the period for which doses are sought to be reconstructed unless it

can be demonstrated that the working conditions, procedures, monitoring methods, and

(perhaps) legal requirements were comparable to the period in question.  

5.    Plausibility:  The manner in which the surrogate data are to be used must be “plausible” with

regard to the reasonableness of the assumptions made.  The plausibility determination should address

issues of:  

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• Scientific plausibility.  Are the assumed models (e.g., bioassay, concentration

gradients) scientifically appropriate?  Have the models been validated (where

feasible) using  actual monitoring data collected in a similar situation?   

• Workplace plausibility.  Are the assumed processes and procedures (including

monitoring) plausible for the facility in question?  Have all of the factors that

could significantly impact exposure been taken into account?  Is adequate

information available about the facility in order to be able to make a fair

assessment?   

Claimants will have significant concerns about the credibility of using surrogate data.  To the extent that

the use of surrogate data for individual dose reconstruction can be avoided, this will help to minimize

concerns about the credibility of the individual dose reconstruction process.  This is especially important

given that the use of surrogate data often relies on information on the operations and characteristics of

industrial facilities operated many years ago.  Many of the people knowledgable about the facility have

died, and records are usually incomplete (which is the reason for needing to use surrogate data in the

first place).  Given the difficulties in obtaining the comprehensive information needed for validating the

use of surrogate data for individual dose reconstruction and the inherent concerns about its use by

claimants, the Work Group recommends that the use of surrogate data be limited to the circumstances

where other approaches are not feasible and then only after the rigorous  review of the proposed use to

determine if the above criteria have been fully met.